Carburetor



March 23 1926. 15779892 C. F. JOHNSON CARBURET OR Filed Deo. 1, 1921 2 sheets`sfhee- 1 March 23 '9526a C. F. JOHNSON CARBURETOR 2 Sheets-Shoo?.

Filed Deo, l,

Snom/Lto@ nd/i250@ 2%? j? @Hoz/new Patented Mai. a3, 1926.

enseres. r. Jonson, or nn'rnorr, mexicain camionero;

Application flied December 1, 1981. 'Serial lo. 519,132.

To all whom-it may concern:

`Be it known that I, CHESTER F. JOHNSON,

a citizen ofthe UnitedStates, and -a res.

ident of Detroit, `county of Wayne, and State of Michigan," have invented certain new and usefulA Improvements in Carburetors, of which the following is a full, clear, concise, and exact descri tion, such as Vwill enable others skilled in t e artto whichl the 1o invention relates to make and use the same,

referencebeino made therein to the accompanying drawings, which form a part of,

v nection with the accompanying drawings,

this specification.`

The invention relates to carburetors and 16 more particularly to means for maintaining proper relative proportions of fuel and air in the' motormixture under variable operat# 'in conditions. v f carburetors of the t pe in whlcha ]et 20 of fluid. fuel is delivere into a mixing I chamber by suction, it is generally. essential, in lorder to obtain a proper mixture, that the level jofl liquid Vin the reservoir from which thejet is supplied ,shouldb'e approximately constant mother words, that the delivery nozzle shall beat a predetermined and constant heightrelative to the level of liquid in thereservoir. This 'is usually at# tained by controllingthe vsupply to the'jres- 80 ervoir by one of the well-known float valve devices. Under certain conditions, however, the oatVvalve/mechanism may be ine'ec-L tive to maintain 'accurately a constant level inthe rservoir,`and the mixture may vary accordingly from theproportions for whic .the carburetor'v-has been adjusted due Ito increased tendenc fofthe liquidto `iiow to fthe nozzlefas, Ythe evelin the reservoir Such condiftrosjma arise when, for exam- 40 plegfthe oatiactua valve in the carburetorjreseri'foir acts A against a variable pres- 'surefas' occur'where thefuel is supplied under a 'variable ,or from a pumping system fini which vaxingpressure mafv be exerted, vo1i\'.;the liqui e height-o the liquid level relativeto .the .`nozz1 e may' also f varjyr with .the inclinationv oavehicle upon which vthe apparatus vmounted,f= as,

for1 e xampl e', where-the nozzle is not'cen-l trallylocated withreference to the bowl Y-or' vcliaxnbe l,or where the action of the viloat itself 'is not uniformi-at dierent inclinations of the apparatus," f

The primary ob'ectof my invention there- 5 fore is the provision of'means whereby vations in inclination of the a paratus such` as'- ed in vthev extension 13.1 In the upp Vin talre o ning f throl h, "ing/.controlled by valve 16 forced 'llblyv *moeheid in the andv capable of'beingadjusted by the elbow support for spring 1 l 1 riations in level in the carburetor supply reservoir, or lioat chamber, may be automatically compensated so that the quality of the mixture shall not be affected thereby.

A further object is the provision of means responsive to changes in liquid level in the reservoir to reduce the pressure of the atmos here above the liquid therein as the level)' rises and permit the pressure to in- E crease as the level falls. Q5

Other objects-and advantages will appear from thefo'llowing description taken in con'- modified `form; and

Fig. 5 is a vertical section showin a de?Y tail of the float xqalve mechanism of igs. 3 or 4.

Figs. 1 and 2 of the drawing's'illustrate la lform of the invention especiallyesig'ned to compensate for changes in level of liquid. adjacent to the fuelnozzledue to variama occur, rfor example, w en a `motor vehic e in which 'the carburetor is employed is travelin "upon inclinedroad surfaces.

In this em ment 10,11 indicate respec-v tively upper and lower parts of a carburetfor body which are 'secured together to enclose between them the mixing chamber 12.,

The upper portion, 10 isprovided with a tubular extension 131adapted to beconnect-` ved in anyusualorsuitable manner' to the 95' intake manifold of an internal combustion engine. v A throttle valve 14 may be mounter face of the'body portion 10 is-an auxlhar air 15,- the ow of air .t ere- 1 00 towar yitsfseatgby springmf.. A lpinf18- y portion 11 screw v20 `provides a. 105

lever -19 Vand adjustln h mb th A ou w e y e a onthereof may be varied.l In :an aperture in the body portion 11 di rectly below the delivery tube or extension 13 is mounted a downwardly tapering'mixl-110 Y face of the liquid in the bowl. Obviously,`

ing .tube 21 the upper part of which extends iabove the floor of the body 11. Perfora- A receptacle or fioat bowl 23 which may be formed integrally with the body 11, as shown, or otherwise suitably secured thereto, encloses a fuel chamber 24. A cover 25 carries a pipe connection 26 adapted to communicate with asuitable source of supply of liquid fuel. Flow to the fuel chamber 24 is cont-rolledfby valve 27 in cooperation with valve seat 28, the valve being actuated to# ward its seat in the usual manner by float 29. An air vent 30 is provided at a suitable location, as in the cover 25.

The bowl 23 is formed with a cup-shaped portion 31 surrounding the lower end of the mixing tube 21 and with a nozzle 32 centrallv located in the cup 31 and extending within the lower end of tube 21. A passage 33 leads lto the nozzle from the chamber 24 and serves to deliver fuel to the nozzle under the iniuence of suction incident to the operation of the engine: It will be noted that the nozzle is located at or near one side of the chamber 24, and that,I as a result, any tilting of the float bowl toward or away from the nozzle'will vary the level adjacent to the nozzle, orthe distance between the delivery orifice yof the nozzle and the surtherefore, a correspondin difference will occur in the stream of liquld drawn into the air current flowing downwardly in cupy 31 and upwardly, past the nozzle, into mixing tube 21, the amount of fuel delivered decreasing as the distance vthrough which it must be lifted increases.

In order to compensate for such change `in level, I provide means for utilizing the suction in the mixing chamber to decrease the atmospheric pressure on the liquid in the fuel chamber as the level in the latter `rises, and vice versa. To this endv I provide by a downwardly tapering valve 35 carriedupon rod 36. The lower end of the rod may be slidably supported in a bearing in flange 37 on the wall of bowl 23. A float 38 mounted upon the rod 36 serves to render the position of valve 35 responsive to the level adjacent to the location of the nozzle. lf new the apparatus should be tilted so that thelevel of fuel adjacent to the nozzle rises, the ioat 33 will also rise, increasing the effective area of the passage 34 and per- Knitting the suction iii the mixing chamber l2 te act to an increasing extent upon the fuel in the fuel l f Joer, or, in other words, to reduce the atmo heric pressure in ch ber the nozzle. A tipping movement in the op- I effect,

to tilting, inasmuch as the nozzle is more centrally located with reference to the bowl, but more particularlyadapted for use with stationary plants in order to compensate for.

variations in level due to other causes, such, for example, as those incident to differences in pressure in the fuel line. Referring es-I pecially to Figs. 3 and 5, 40 indicates a carburetor body enclosing a mixing chamber 41. An extension 42 is adapted for attachment to the usual manifold and supports a throttle valve 43. An air valve 44 controls the lowof auxiliary air through the intake 45. The bottom of the body 40 is formed with an aperture over which is arranged'a diaphragm 46 inclined downwardly at its central portion. A downwardly tapered mixing tube 47 is supported in the centraly depression of ldiaphragm 46 and apertures 48 provide for drainage from the mixing chamber. .A float bowl 49 encloses the fuel chamber 50 and has a cover 51 suitably secured, as by screws 52, to the body 40. A fuel nozzle tube 53 may be threaded, as at 54, into anv aperture in cover 51 and extends within the lower end of mixing tube 47. Openings, as at 55, at the lower end of tube 53 ,permit fuel to enter the tube from chamber 50, and the lower end of tube 53-may be screwthreaded, as at v56, to receive a screw plug 57 whereby the bowl 49 is clamped tothe of cover`51 to ermit entry of airV below diaphragm 46, w ich openings are shielded by the downwardly turned flange 62 on the diaphragm. Air entering theopenings 61 passes to the lower end of mixing tube 47 whence it flows upwardly around the nozzle and mixes with the stream of fuel supplied from the nozzle. The usual air vent may be provided, as at 63. 'y

Communicating with the fuel chamber 50 both above and below the fuel level therein is the guideway or chamber 64 in which the float 65v is adapted to move vertically in response to changesin level of the liquid in chamber 50. An aperture 66 is formed in the wall between the mixing chamber 41 and fuel chamber 50 providing a passage whereby the suction in chamber 4l may be exerted to reduce the pressure in chamber 50. The flow cf` air through this passage is contrailed by valve 67 mounted upon rod63 which is carried by fioat 65. As the level of liquid in chamber 50 rises, therefore, the

67 lifted the pressure upon the for communication between the mixingl chamberv and the fuel chamber consists of a channel 70 opening through a transverse passage .to the mixing chamber at `71 and to the exterior atmosphere at 72. The flow of kair into the transverse passage through 3theiport 72 is controlled by a valve'member 7 3 mounted upon the upper end of the rod 68' carried by fioats 65. In the operation. of this form ofthe apparatus the effect of suctionin the mixing chamber in reducing the pressure in thefuel chamber Will be increased as the port 72 is closed and lessened as'the port is opened. The pressure onthe liquid in the fuel chamber is therefore varied inv response to changes, in levelv therein as in the'forms previously described.

While in the foregoing description I have referred specifically to the control of flow of the liquid fuel bygvarying -the atmospheric pressure upon the surface of the fuel,

i will be understood that such control may be effected by any desired form of oburating or lflow controlling means acting directly or otherwise to counteract the increased tendency. of the fuel to flow toward the mixing chamber due to rise of level in thesupply chamber, and it will be appreciated that the invention will include within its scope all such', Variations and modifications covered by the language of the appendypressure within the fuel chamber, it will f obvious'that such variation may be effected ed claims and adapted to perform the funcf p. tion specified. Furthermore, in embodiments of the invention wherein provision is madey for automatic var1at1on of the atmospheric otherwise than by connection to the mixing chamber, hence I do not desire to be limited, in the broader aspects of the invention, to the utilization of sub-atmospheric pressure or connection to the mixing chamber only.

This application is designed as a substitute for my application Serial bld-74,754, filed January. 28,1916, and'is a continuation thereof insofar as the `two applications includecommon subject matter.

I claim:

l. In a carburetor, in combination, a

' vented fuelv chamber, means for regulatingl the How of fuel thereto, a mixing chamber,

said fuel chamber arranged to supply .fuel to said mixing chamber, a passage con necting said chambers, and means actuated by the liquid in said fuel chamber 'for controlling iow throughV said passage to applyv suction increasingly to said fuel chamber as ,the fuel therein rises.

2. In a carburetor, the combination of a float chamber, a mixing chamber, means for delivering fluid fuel from sai-(l float chamber to said mixing chamber, and valve means adapted to be actuated by the fuel in said float chamber and operative to cause an increasing retardation in the flow of fuel from said float chamber to said mixing chamber as the level of fuel in said float chamber rises.

3. In a carburetor, the combination ofa fuel chamber, means for regulating the flow of fuel thereto, a mixing chamber, a fuel nozzle feeding fuel thereto, means for Supplying air to said mixing chamber, said fuel chamber and said mixing chamber being provided with a connecting air passage, and a Vfloat valve for regulating the action of the suction of said mixing chamber on the surface of the fuel of the said fuell chamber through said passage.

4. A carburetor comprising, a nozzle subject to suction, `a fuel chamber Subject to suction from the same source as that for the nozzle for supplying fuel to said nozzle, and

means responslve to the level of fuel in said chamber tending to increase the absolute pressure in said chamber upon decrease of the fuel level therein and vice versa, to thereby tend to maintain the quality of the mixture vconstant throughout variations in the level of fuel in said chamber.

5. Incombination, a mixing chamber, a

kthe fuel therein rises..

6. In a carburetor, a mixing chamber, a

nozzle arranged to supply fluid fuel to'said mixing chamber, a fuel chamber adapted to feed fuelto said nozzle, and means responsiveto the level of fuel in saidfuel chamber operative to counteract the increased tendency of fuel to flow to said nozzle due to rise-of said level.

7. In combination, a mixing chamber, afuel chamber, float controlled means for supplying liquid fuel thereto, a nozzle for feedf ing liquid fuel from said fuel chamber to said mixing. chamber, said nozzle so positioned that the liquid adjacent thereto in said fuelchamber is subject to Variations in level withvariations in inclination of said parts, 'and means forvreducing the atmospheric pressure. in said fuel chamber in accordance with the rise in said level.

8. In combination, a mixing chamber, a fuel chamber, float controlled means for supplying li uid fuel thereto, a nozzle for feeding liqui fuel from said fuel chamber to said mixing chamber, said nozzle so posi- Y tioned that the liquid adjacent theretovin said fuel chamber is subject to variations \in level with variations in ,inclination of said parts, and means for reducing the at- 5 lmospheric pressure in Said fuel chamber in accordance with the rise in'sad level, said means comprising a passage between said l 1,577,3023` Y l cl'mmbers,'aV valve adapted vto vary the area v of said passa e, and a float responsiverto level in said uel chamber and Yadapted to 10 actate sidvalve. l

In'testimony whereof I alix my signature.

CHESTER F. JoHNsoN. 

